A new species Ophichthus chennaiensis sp. nov. (Anguilliformes: Ophichthidae) from the southeast coast of India

A new species of snake eel, Ophichthus chennaiensis sp. nov. (Anguilliformes: Ophichthidae: Ophichthinae), is described on the basis of a specimen collected from dumped fish disposed of by bottom trawlers at Kasimedu fishing harbour, Chennai. Ophichthus chennaiensis sp. nov is distinguished from its congeners by having its dorsal-fin origin one pectoral-fin length behind the pectoral-fin tip, preanal length 2.4 in TL, biserial maxillary, uniserial mandibular teeth, biserial to uniserial vomerine teeth, and its vertebrae (predorsal 19, preanal 53, and total vertebrae 154).

Exostoma dulongensis, a new glyptosternine catfish from the Irrawaddy basin, Yunnan, China (Siluriformes: Sisoridae)

Exostoma dulongensis sp. nov., a new species of sisorid catfish from the genus Exostoma Blyth, 1860, is described from the Xiaojiang River and Dulongjiang River, tributaries of N’mai Hka River in the Irrawaddy basin, Yunnan Province, China. Exostoma dulongensis sp. nov. is the seventeenth species reported within this genus and is most similar to Exostoma ericinum Ng 2018 in morphology but can be distinguished by the following characters: tip of pelvic fin far from anus vs. reaching when depressed; nasal barbel reaching or surpassing posterior edge of orbit vs. just reaching middle of orbit; greater preanal length (70.9%–80.1% SL vs. 67.7%–70.5%); and longer dorsal to adipose length (13.5%–23.8% SL vs. 8.0%–12.0%). The new species can also be distinguished from all known congeners by the following characters: adipose fin confluent with caudal fin and without incision; caudal fin weakly forked; 40–43 vertebrae; and pectoral fin extending to vicinity of dorsal fin origin.

Ophichthus kailashchandrai sp. nov. (Anguilliformes: Ophichthidae): a new species of snake eel from Indian waters, Bay of Bengal

A new snake eel (Anguilliformes: Ophichthidae: Ophichthinae) species, Ophichthus kailashchandrai sp. nov., is described from three specimens, collected from the Shankarpur fishing harbour located on the northern part of the Bay of Bengal, West Bengal, India. Ophichthus kailashchandrai sp. nov. is distinguished from its congeners by having its dorsal-fin origin at the posterior third of the pectoral fin, preanal length 2.6–2.8 in TL, uniserial maxillary and mandibular teeth and vertebral count (predorsal vertebrae 14–15, preanal vertebrae 54–55, and total vertebrae 180–182).

Review of the moray eels (Anguilliformes: Muraenidae) of the Red Sea, with description of a new species

Thirty-eight species of moray eels (Muraenidae) from the Red Sea are reported in an updated review. A species account is provided for each species, along with a full synonymy of all nominal species described from the Red Sea. One species is new to science, G. pharaonis, and two species are new for the Red Sea, Gymnothorax phasmatodes (Smith) and Scuticaria tigrina (Lesson). Gymnothorax pharaonis n. sp. is a common species that has long been misidentified as G. undulatus (Lacepède), although it more closely resembles G. margaritophorus Bleeker, to which it is closely related phylogenetically. It is characterized by the following combination of characters: total vertebrae 123–128; body slender, depth at anus 17–28 in TL; maxillary teeth biserial, dentary and vomerine teeth in a single row; color brown with irregular dendritic pale markings, not interconnected or chain-like, with oblique, conspicuous, parallel streaks posteriorly in dorsal fin. The new record of the distinctive whitish G. phasmatodes is based on an underwater photograph taken at Jeddah, Saudi Arabia. The new record of Scuticaria tigrina is based on a specimen collected from Jeddah, Saudi Arabia, and underwater photographs taken from the northern part of the Red Sea. Based on an integrative taxonomical approach by a combination of morphological and phylogenetic analyses and re-examination of holotype specimens, Gymnothorax cinerascens (Rüppell) is resurrected as a valid species, and it is shown that previous records of G. hepaticus (Rüppell), with which it has previously been synonymized, should refer to G. cinerascens. The true G. hepaticus is redescribed based on examination of the holotype and additional specimens collected during the course of this study. The two species are distinguished by the color of the jaws, the position of the median intermaxillary teeth, and a slight difference in the preanal length. They are also clearly distinct genetically. The Red Sea record of Gymnothorax atolli (Pietschmann) is based on an error, possibly a misidentification of G. griseus (Lacepède). A key to the species of Red Sea moray eels and a phylogenetic tree of presently known lineages of Indo-Pacific moray eels are provided including recently collected Red Sea specimens.

Review of the Stemonosudis rothschildi species complex, with descriptions of two new species from the Indo-west Pacific Ocean (Aulopiformes: Paralepididae)

Three barracudina species are recognized in the Stemonosudis rothschildi species complex, which includes Stemonosudis rothschildi Richards, 1967, and two new species described herein. Stemonosudis multifasciatus sp. nov. is described based on five specimens collected off northwestern Australia and Myanmar, Eastern Indian Ocean. It is characterized by having 16 brownish blotches on dorsum (10 before dorsal-fin origin); 49–51 caudal vertebrae; 93‒95 total vertebrae; dorsal-fin origin relatively forward in position, distance between origins of pelvic and dorsal fins 52.3‒63.0% of distance between origins of pelvic and anal fins; and combination of body proportions. Stemonosudis retrodorsalis sp. nov. is described based on 15 specimens collected from off the Philippines, Indonesia and northwestern Australia. It is characterized by having dorsal-fin origin at about vertical through anal-fin origin, insertion of anal fin relatively forward, preanal length 71.5‒79.5% SL; 6 blotches on dorsum before DFO and 4 on abdominal ridge before VFO and unique combination of body proportions. A redescription of S. rothschildi, based on specimens collected from off Dongsha (Pratas) Islands, Australia and West Indies, is also included.

Observations on the ontogeny of butterfish Stromateus stellatus larvae (Pisces: Stromateidae) off central Chile

Although larvae of the starry butterfish Stromateus stellatus (Family Stromateidae) are often observed in coastal waters of the southeastern Pacific Ocean, there is no formal description of the species’ early development. Using ichthyoplankton samples collected off central Chile, the larval development, including observations on osteology of late postflexion stage larvae, and temporal differences in larval densities in nearshore waters are described. Preflexion larvae have a short, rounded snout and a distinctive pigment pattern. Notable transformations throughout the development from early preflexion to postflexion are the increase in preanal length from less than 40 to more than 50% of body length (BL) and in body depth from 5 to 33% BL. Initially, larvae develop 3 melanophores on the dorsal contour of the body, small melanophores at the jaw angle, and a row along the ventral margin of the tail. Large melanophores dorsal and ventral to the gut, intestine, and above the swim bladder are also present in early preflexion. After notochord flexion, larvae develop light pigmentation on the sides of the tail, and heavy pigmentation on the head and trunk. The larvae share the general shape of the family, with a body that increases notably in depth and preanal length during development; they present characteristic pigmentation that differentiates them from larvae of related species. The larvae were recorded in low density (less than 6 ind. 100 m-3) in the nearshore during mid-spring (October) and early summer (late December until mid-January) off central Chile. The occurrence of the larvae in the plankton recorded in central Chile is consistent with information from literature of larval distribution and reproductive activity in adults.

The eel genus Macrocephenchelys (Anguilliformes: Congridae) in Taiwan, with description of a new species

The congrid eel genus Macrocephenchelys in Taiwan is reviewed. Three species are recognized. Macrocephenchelys brachialis was originally described from Indonesia and is also known from Taiwan, Madagascar, and Vanuatu; it is common in Taiwan but known from few specimens elsewhere. Macrocephenchelys brevirostris was described from Taiwan, where it is common; its occurrence outside Taiwan is uncertain. Macrocephenchelys nigriventris sp. nov. is described here from 28 specimens collected in Taiwan. Macrocephenchelys brachialis is distinguished from the other two species by its more elongate body, more posterior dorsal-fin origin (behind tip of pectoral fin), shorter head (less than 10% total length), presence of a supratemporal pore, absence of fleshy papillae dorsally on the head, absence of sensory pits on the abdomen, and more than 170 vertebrae. Macrocephenchelys nigriventris is distinguished from M. brevirostris by the presence of a patch of black pigment around the anus and adjacent abdomen (absent in M. brevirostris), preanal length 24–28% total length (27–34% in M. nigriventris), and 128–135 vertebrae (147–154 in M. brevirostris). The only other species currently recognized is M. soela from Australia; it is distinguished from all the others by the more anterior origin of the dorsal fin, over the middle of the pectoral fin (vs. over or behind the tip of the pectoral fin).

Three new species of the cutthroat eel genus Dysomma, with comments on the variation of D. taiwanense (Anguilliformes: Synaphobranchidae)

Three new species of eels of the genus Dysomma are described from the western North Pacific Ocean off Taiwan. Dysomma formosa sp. nov., described from 34 specimens, differs from the congeners in having single row of 11–14 large compound teeth followed by 3–10 smaller teeth on lower jaw, 17–33 lateral-line pores, and 128–133 total vertebrae. Dysomma brachygnathos sp. nov., described from two specimens, differs from the congeners in the lack of a pectoral fin, having an anterior position of anus (preanal length 17.8–ca. 18.6% SL), 23–32 lateral line pores, a short lower jaw, and 131+‒136 total vertebrae. Dysomma robinsorum sp. nov., described from four specimens, differs from the congeners in having an anterior position of anus; preanal length 15.5–16.9% SL, no intermaxillary teeth; multiple rows of teeth on upper jaw; four compound teeth on vomer; teeth on lower jaw multiserial, those on inner row slightly enlarged, and 122–124 total vertebrae. Components of the variation of Dysomma taiwanense originally described from Taiwan are provided based on an additional 52 recently identified specimens.

Exostoma ericinum, a new glyptosternine catfish from southwestern China (Teleostei: Siluriformes: Sisoridae)

A new species of glyptosternine catfish in the genus Exostoma is described in this study. The new species, E. ericinum, is known from the upper Dayingjiang (=Taping River) drainage in southwestern China and is distinguished from congeners in having an unique combination of the following characters: 42–44 vertebrae; parallel striae on anterolateral surfaces of lips and lower surface of maxillary barbel; interorbital distance 26–31% HL; preanal length 67.7–70.5% SL; body depth at anus 10.4–12.0% SL (1.4–1.9 times in caudal peduncle depth); length of adipose-fin base 39.5–43.0% SL; lacking an incision at posterior extremity of adipose-fin base; caudal peduncle length 23.2–26.2% SL; caudal peduncle depth 5.7–7.9% SL; and caudal-fin lobes with slightly concave posterior margin.

Gymnothorax visakhaensis sp. nov., a new species of elongate unpatterned moray eel (Muraenidae: Muraeninae) from the Indian Coast

An elongate, brown unpatterned moray eel, Gymnothorax visakhaensis sp. nov., is described based on seven specimens collected from the Visakhapatnam fishing harbour, Andhra Pradesh, India. The new species is differentiated from other elongate unpatterned moray eels in having the following combination of characters: anus at about mid-point of body, preanal length 1.9–2.1 in total length; snout blunt and short; dorsal-fin margin black, 6 mandibular pores; intermaxillary teeth biserial; maxillary teeth uniserial, sharp and depressible, pre-dorsal vertebrae 7, pre- anal vertebrae 70–74, total vertebrae 163–169.